1. Field of the Invention
The present invention relates to a radiotherapeutic bed apparatus, and particularly to a radiotherapeutic bed apparatus suited to being incorporated into a particle beam therapeutic apparatus that irradiates the affected area of a patient with ion beams.
2. Description of the Related Art
In a radiotherapeutic bed apparatus, a bed on which a patient lies is inserted into a therapy room formed in a rotating gantry, and is aligned with an irradiation device (irradiation field forming device) provided in the rotating gantry. In this situation, the affected area of the patient lying on the bed is positioned on the extension line of the path of ion beams in the irradiation device. The particle beam therapeutic apparatus includes an accelerator and the irradiation device. Ion beams accelerated by the accelerator are applied from the irradiation device to the affected area of the patient lying on the bed.
As an example of a radiotherapeutic bed apparatus (hereinafter, simply referred to as a “bed apparatus”), a bed apparatus disclosed in JP, A 11-313900 is known. As shown in FIG. 2 in the above patent document, this bed apparatus includes a bed on which a patient to lie; an X-axis direction moving device for moving the bed in the X-axis direction; a Y-axis direction moving device for moving the bed in the Y-axis direction; a Z-axis direction moving device for moving the bed in the Z-axis direction; a rotation drive device for rotating the bed; a pitching drive device for driving the bed to pitch, and a rolling drive device for driving the bed to roll.
More specifically, in the bed apparatus shown in FIG. 2 in the JP, A 11-313900, the Z-axis direction moving device is disposed on the X-axis direction moving device, and the Y-axis direction moving device is disposed on the Z-axis direction moving device. A bed base to be rotated by the rotation drive device is disposed on the Y-axis direction moving device; a rotational base to be driven to roll by the rolling drive device is disposed on the bed base; and the therapeutic bed to be driven to pitch by the pitching drive device is disposed on the rotational base. Also, in another bed apparatus shown in FIGS. 12 and 13 in the JP, A 11-313900, a hinge base to be driven to pitch by a pitching drive device is disposed on a bed base, and a radiotherapy bed to be driven to roll by a rolling drive device is disposed on the hinge base.